At some unknown moment in time the Atlanteans were forced to enter armed conflict with the Vortex aliens in an attempt to prevent them from stripping Earth of all life. The Atlanteans predicted that the harvest storms, which occured every 500 years, were increasing in severity with every occurence. They concluded that the Vortex would eventually feed at an unsustainable rate.
How the war was fought is left ambiguous. A glyph in the Atlantean library states that "Atlantis is losing a war with the planet Vortex", implying the war was not a single conclusive event. However, the end of the war is known. As documented in the Atlantean library, Atlantis was ruined when "a beam struck from space." This attack, presumably from the planet Vortex, is almost certainly the event that caused the sinking of Atlantis. The Atlantean people were not completely destroyed; they used their time machine to escape into Earth's past.
From this point on the Vortex aliens could enage in their harvests of the Earth every five-hundred years without any other known resistance until the events of Ecco the Dolphin.
- See also: theories.